If you buy a $20 World of Warcraft Token in North America right now you can sell it for 21,410 gold - in less than 30 minutes - using the game's Auction House.
That's an automatic price set by Blizzard - you can't alter it.
The starting worth of the WOW Token - which launched in the Americas, Australia and New Zealand earlier this week - was 30,000 gold. The price fluctuates depending on supply and demand across an entire server region, not an individual server.
That means a lot of people in North America are buying WOW Tokens. You can track the price live, and see how it has fluctuated in previous days or hours, at a handy site called WOW Token Info (via PC Gamer).
The WOW Token hasn't launched in Europe and there's no specific word on when it will. It's TBC - presumably coming very soon.
WOW Tokens also grant 30 days of game time, which makes them desirable for people with lots of in-game gold to buy. On the one hand it allows time-rich people to effectively play for free, while on the other hand it allows money-rich people a legitimate way of buying gold without using a third-party gold-selling site - a practice that is against the game's rules.